Stay and shroud tension

[marc]

Raised the mast in my driveway. Last year I used a toggle on my forestay to slightly extend the forestay's length and give me more options in making adjustments to my mast rake. Well my toggle went missing. I've read other posts that say as long as the mast is perpendicular to the water, the boat will be balanced. I can achieve a perpendicular mast without the toggle but if I wanted to rake the mast back at all, then I'd need to purchase another one. So my 1st question is whether any of you feel you need to rake your mast back?

In playing around though, I got wondering what tensions the shrouds and stays ought to be. I have a Loos guage. The instructions suggest a forestay tension of 15% of breaking strength. Breaking strength for 5/32" wire is 3300 lbs giving a target tension of 495. Can't measure the forestay tension on my boat since the wire itself is encased by the furler's foil. When I tighten the backstay to where I think it is plenty tight, I measure less than 200 pounds on the guage (200 pounds is the minimum tension the Loos guage shows for this wire diameter.) So my second question is - am I being too paranoid? Should I tension the backstay up to say 250 or 300 pounds? The Loos instructions say " Backstay tension would, of course, have to be adjusted to maintain a straight mast with the desired forestay tension. Since the backstay makes a greater angle to the mast, the backstay tension will be lower than the forestay tension."

As far a shrouds go, the instructions do not recommend specific tensions but instead says "the leeward shrouds don't go slack when close-hauled in a reasonably stiff breeze. The proper value for your boat can be found by a few trial runs under sail. Once the correct tension is known, the guage can be used to maintain this value."

The compac manual does not say anything other than tighten the stays until they are tight.

Any thoughts would be appreciated.

[MacGyver]

For one thing, as far as I know, you cannot make rake in a mast head rig. I think that can only be done in a fractional rig.

Maybe Some could be added if you lowers sweep forward.... but I believe they sweep back a little so that wont gain any rake value.

On my 19, I have the forestay set and the pins locked inside since it is now setup with a furler. The backstay is used to put the proper tension in the rig, which I do just by hand then the side stays are adjusted according to what they do under sail.

In a stiff breese, running along nicely my lee shrouds will loop a little. Maybe mine need to be tighter...... But I like the way they feel as I get around the boat.
Also I tune the rig overall by checking the mast track for straightness. That seems to tell a lot and you can prior to side adjustment just pull on the one you think needs it and see the difference right away first.

Mac

[Craig]

Google "tuning the masthead rig". Many good articles on tuning your rig. Mac is right, the only effective way of adjusting rake on a masthead rig is moving the mast fore or aft on the step. Inducing fore or aft mast BEND by adjusting fore/backstay tension allows you to flatten or increase the draft of your sail.

[marc]

I guess I've been doing it right all along by just hand tightening the wires. Get the mast straight and then observe the wires under sail to see if they need additional tweeking. Craig - I did google the topic as you suggested and read 4 articles.  One talked about using specific tension values. The other 3 just said to tighten by hand and apply more turns only if necessary. Basically adjust the backstay until you are happy with your forestay tension. Shrouds just tight enough so you are leeward wires aren't loose.
Thanks guys. The boat goes in Thursday morning.

[crazycarl]

here is a link to a post from 2011...

http://cpyoa.geekworkshosting.com/forum/index.php?topic=4066.msg28260#msg28260

[skip1930]

After the stick is up, if possible walk down the dock and look~see if the mast is straight up and down.

Next crawl into the Vee Birth of a CP-19 and sight up the mast. It should be straight as Earl Flynn.
Yes you can see the lower shrouds, and upper shrouds pulling curves into the mast. Fix that first.

When sailing the lee side shrouds will be a tad loose.

and

When sailing the windward side shrouds will be tight.

Be mindful that shrouds which are really tight will tend to shove the mast through the bottom of the cabin top, hence the need for a compression post.

skip. I don't over think this.

These boats are not Star Boats where a curve is induced into a noodle-like spruce mast for optimum sail shapes.

[marc]

Put the mast up and went for my 1st sail. The leeward lower shrouds were just a tad floppy. I'll probably put 1 more  turn on them. Skip - I forgot about laying in the V-berth and sighting up the mast through the hatch. I'll do that on my next visit.

The real pleasure from this 1st sail was using the Ruddercraft rudder. I was reefed and not using the jib and I still could tack. That just was not possible with the stock rudder. A very nice upgrade.